/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is the Mozilla browser.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications, Inc.
 * Portions created by the Initial Developer are Copyright (C) 1999
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Travis Bogard <travis@netscape.com>
 *   Darin Fisher <darin@meer.net>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include "nsISupports.idl"

interface nsIWebProgress;
interface nsIRequest;
interface nsIURI;

/**
 * The nsIWebProgressListener interface is implemented by clients wishing to
 * listen in on the progress associated with the loading of asynchronous
 * requests in the context of a nsIWebProgress instance as well as any child
 * nsIWebProgress instances.  nsIWebProgress.idl describes the parent-child
 * relationship of nsIWebProgress instances.
 *
 * @status FROZEN
 */
[scriptable, uuid(570F39D1-EFD0-11d3-B093-00A024FFC08C)]
interface nsIWebProgressListener : nsISupports
{
  /**
   * State Transition Flags
   *
   * These flags indicate the various states that requests may transition
   * through as they are being loaded.  These flags are mutually exclusive.
   *
   * For any given request, onStateChange is called once with the STATE_START
   * flag, zero or more times with the STATE_TRANSFERRING flag or once with the
   * STATE_REDIRECTING flag, and then finally once with the STATE_STOP flag.
   * NOTE: For document requests, a second STATE_STOP is generated (see the
   * description of STATE_IS_WINDOW for more details).
   *
   * STATE_START
   *   This flag indicates the start of a request.  This flag is set when a
   *   request is initiated.  The request is complete when onStateChange is
   *   called for the same request with the STATE_STOP flag set.
   *
   * STATE_REDIRECTING
   *   This flag indicates that a request is being redirected.  The request
   *   passed to onStateChange is the request that is being redirected.  When a
   *   redirect occurs, a new request is generated automatically to process the
   *   new request.  Expect a corresponding STATE_START event for the new
   *   request, and a STATE_STOP for the redirected request.
   *
   * STATE_TRANSFERRING
   *   This flag indicates that data for a request is being transferred to an
   *   end consumer.  This flag indicates that the request has been targeted,
   *   and that the user may start seeing content corresponding to the request.
   *
   * STATE_NEGOTIATING
   *   This flag is not used.
   *
   * STATE_STOP
   *   This flag indicates the completion of a request.  The aStatus parameter
   *   to onStateChange indicates the final status of the request.
   */
  const unsigned long STATE_START          = 0x00000001;
  const unsigned long STATE_REDIRECTING    = 0x00000002;
  const unsigned long STATE_TRANSFERRING   = 0x00000004;
  const unsigned long STATE_NEGOTIATING    = 0x00000008;
  const unsigned long STATE_STOP           = 0x00000010;


  /**
   * State Type Flags
   *
   * These flags further describe the entity for which the state transition is
   * occuring.  These flags are NOT mutually exclusive (i.e., an onStateChange
   * event may indicate some combination of these flags).
   *
   * STATE_IS_REQUEST
   *   This flag indicates that the state transition is for a request, which
   *   includes but is not limited to document requests.  (See below for a
   *   description of document requests.)  Other types of requests, such as
   *   requests for inline content (e.g., images and stylesheets) are
   *   considered normal requests.
   *
   * STATE_IS_DOCUMENT
   *   This flag indicates that the state transition is for a document request.
   *   This flag is set in addition to STATE_IS_REQUEST.  A document request
   *   supports the nsIChannel interface and its loadFlags attribute includes
   *   the nsIChannel::LOAD_DOCUMENT_URI flag.
   * 
   *   A document request does not complete until all requests associated with
   *   the loading of its corresponding document have completed.  This includes
   *   other document requests (e.g., corresponding to HTML <iframe> elements).
   *   The document corresponding to a document request is available via the
   *   DOMWindow attribute of onStateChange's aWebProgress parameter.
   *
   * STATE_IS_NETWORK
   *   This flag indicates that the state transition corresponds to the start
   *   or stop of activity in the indicated nsIWebProgress instance.  This flag
   *   is accompanied by either STATE_START or STATE_STOP, and it may be
   *   combined with other State Type Flags.
   *
   *   Unlike STATE_IS_WINDOW, this flag is only set when activity within the
   *   nsIWebProgress instance being observed starts or stops.  If activity
   *   only occurs in a child nsIWebProgress instance, then this flag will be
   *   set to indicate the start and stop of that activity.
   *
   *   For example, in the case of navigation within a single frame of a HTML
   *   frameset, a nsIWebProgressListener instance attached to the
   *   nsIWebProgress of the frameset window will receive onStateChange calls
   *   with the STATE_IS_NETWORK flag set to indicate the start and stop of
   *   said navigation.  In other words, an observer of an outer window can
   *   determine when activity, that may be constrained to a child window or
   *   set of child windows, starts and stops.
   *
   * STATE_IS_WINDOW
   *   This flag indicates that the state transition corresponds to the start
   *   or stop of activity in the indicated nsIWebProgress instance.  This flag
   *   is accompanied by either STATE_START or STATE_STOP, and it may be
   *   combined with other State Type Flags.
   *
   *   This flag is similar to STATE_IS_DOCUMENT.  However, when a document
   *   request completes, two onStateChange calls with STATE_STOP are
   *   generated.  The document request is passed as aRequest to both calls.
   *   The first has STATE_IS_REQUEST and STATE_IS_DOCUMENT set, and the second
   *   has the STATE_IS_WINDOW flag set (and possibly the STATE_IS_NETWORK flag
   *   set as well -- see above for a description of when the STATE_IS_NETWORK
   *   flag may be set).  This second STATE_STOP event may be useful as a way
   *   to partition the work that occurs when a document request completes.
   */
  const unsigned long STATE_IS_REQUEST     = 0x00010000;
  const unsigned long STATE_IS_DOCUMENT    = 0x00020000;
  const unsigned long STATE_IS_NETWORK     = 0x00040000;
  const unsigned long STATE_IS_WINDOW      = 0x00080000;


  /**
   * State Security Flags
   *
   * These flags describe the security state reported by a call to the
   * onSecurityChange method.  These flags are mutually exclusive.
   *
   * STATE_IS_INSECURE
   *   This flag indicates that the data corresponding to the request
   *   was received over an insecure channel.
   *
   * STATE_IS_BROKEN
   *   This flag indicates an unknown security state.  This may mean that the
   *   request is being loaded as part of a page in which some content was
   *   received over an insecure channel.
   *
   * STATE_IS_SECURE
   *   This flag indicates that the data corresponding to the request was
   *   received over a secure channel.  The degree of security is expressed by
   *   STATE_SECURE_HIGH, STATE_SECURE_MED, or STATE_SECURE_LOW.
   */
  const unsigned long STATE_IS_INSECURE     = 0x00000004;
  const unsigned long STATE_IS_BROKEN       = 0x00000001;
  const unsigned long STATE_IS_SECURE       = 0x00000002;

  /**
   * Security Strength Flags
   *
   * These flags describe the security strength and accompany STATE_IS_SECURE
   * in a call to the onSecurityChange method.  These flags are mutually
   * exclusive.
   *
   * These flags are not meant to provide a precise description of data
   * transfer security.  These are instead intended as a rough indicator that
   * may be used to, for example, color code a security indicator or otherwise
   * provide basic data transfer security feedback to the user.
   *
   * STATE_SECURE_HIGH
   *   This flag indicates a high degree of security.
   *
   * STATE_SECURE_MED
   *   This flag indicates a medium degree of security.
   *
   * STATE_SECURE_LOW
   *   This flag indicates a low degree of security.
   */
  const unsigned long STATE_SECURE_HIGH     = 0x00040000;
  const unsigned long STATE_SECURE_MED      = 0x00010000;
  const unsigned long STATE_SECURE_LOW      = 0x00020000;


  /**
   * Notification indicating the state has changed for one of the requests
   * associated with aWebProgress.
   *
   * @param aWebProgress
   *        The nsIWebProgress instance that fired the notification
   * @param aRequest
   *        The nsIRequest that has changed state.
   * @param aStateFlags
   *        Flags indicating the new state.  This value is a combination of one
   *        of the State Transition Flags and one or more of the State Type
   *        Flags defined above.  Any undefined bits are reserved for future
   *        use.
   * @param aStatus
   *        Error status code associated with the state change.  This parameter
   *        should be ignored unless aStateFlags includes the STATE_STOP bit.
   *        The status code indicates success or failure of the request
   *        associated with the state change.  NOTE: aStatus may be a success
   *        code even for server generated errors, such as the HTTP 404 error.
   *        In such cases, the request itself should be queried for extended
   *        error information (e.g., for HTTP requests see nsIHttpChannel).
   */
  void onStateChange(in nsIWebProgress aWebProgress,
                     in nsIRequest aRequest,
                     in unsigned long aStateFlags,
                     in nsresult aStatus);

  /**
   * Notification that the progress has changed for one of the requests
   * associated with aWebProgress.  Progress totals are reset to zero when all
   * requests in aWebProgress complete (corresponding to onStateChange being
   * called with aStateFlags including the STATE_STOP and STATE_IS_WINDOW
   * flags).
   *
   * @param aWebProgress
   *        The nsIWebProgress instance that fired the notification.
   * @param aRequest
   *        The nsIRequest that has new progress.
   * @param aCurSelfProgress
   *        The current progress for aRequest.
   * @param aMaxSelfProgress
   *        The maximum progress for aRequest.
   * @param aCurTotalProgress
   *        The current progress for all requests associated with aWebProgress.
   * @param aMaxTotalProgress
   *        The total progress for all requests associated with aWebProgress.
   *
   * NOTE: If any progress value is unknown, or if its value would exceed the
   * maximum value of type long, then its value is replaced with -1.
   */
  void onProgressChange(in nsIWebProgress aWebProgress,
                        in nsIRequest aRequest,
                        in long aCurSelfProgress,
                        in long aMaxSelfProgress,
                        in long aCurTotalProgress,
                        in long aMaxTotalProgress);

  /**
   * Called when the location of the window being watched changes.  This is not
   * when a load is requested, but rather once it is verified that the load is
   * going to occur in the given window.  For instance, a load that starts in a
   * window might send progress and status messages for the new site, but it
   * will not send the onLocationChange until we are sure that we are loading
   * this new page here.
   *
   * @param aWebProgress
   *        The nsIWebProgress instance that fired the notification.
   * @param aRequest
   *        The associated nsIRequest.  This may be null in some cases.
   * @param aLocation
   *        The URI of the location that is being loaded.
   */
  void onLocationChange(in nsIWebProgress aWebProgress,
                        in nsIRequest aRequest,
                        in nsIURI aLocation);

  /**
   * Notification that the status of a request has changed.  The status message
   * is intended to be displayed to the user (e.g., in the status bar of the
   * browser).
   *
   * @param aWebProgress
   *        The nsIWebProgress instance that fired the notification.
   * @param aRequest
   *        The nsIRequest that has new status.
   * @param aStatus
   *        This value is not an error code.  Instead, it is a numeric value
   *        that indicates the current status of the request.  This interface
   *        does not define the set of possible status codes.  NOTE: Some
   *        status values are defined by nsITransport and nsISocketTransport.
   * @param aMessage
   *        Localized text corresponding to aStatus.
   */
  void onStatusChange(in nsIWebProgress aWebProgress,
                      in nsIRequest aRequest,
                      in nsresult aStatus,
                      in wstring aMessage);

  /**
   * Notification called for security progress.  This method will be called on
   * security transitions (eg HTTP -> HTTPS, HTTPS -> HTTP, FOO -> HTTPS) and
   * after document load completion.  It might also be called if an error
   * occurs during network loading.
   *
   * @param aWebProgress
   *        The nsIWebProgress instance that fired the notification.
   * @param aRequest
   *        The nsIRequest that has new security state.
   * @param aState
   *        A value composed of the Security State Flags and the Security
   *        Strength Flags listed above.  Any undefined bits are reserved for
   *        future use.
   *
   * NOTE: These notifications will only occur if a security package is
   * installed.
   */
  void onSecurityChange(in nsIWebProgress aWebProgress,
                        in nsIRequest aRequest,
                        in unsigned long aState);
};
